Chemical heating pad



M. A'. SMITH CHEMICAL HEATING PAD March 8, 1927..r`

Filed Dep. 17. 1924 INVENTO R /W/ DREa/ SM/r VBY ATTORNEYS WITNESSESPatented Mar. 8, 1927.

UNITED STATES PATENT OFFICE.

MBDRED'AURELIA SMITH, or AIQBANY, NEW YORK.

p cH'EMeAL HEATING ran.

Application led December 17, 1924. Serial No. 756,587.

' simple and eiiicient means for causing the venting thewater ofcondensation inside ofv ,iron' borings that have prevlously bag to foldtwhen-closing, at a point where said Ibag cannot leak. A further objectconcerns the provision of simple and eiiicient means for maintainlng aneven temperature in all parts of the chemical mixture.

-A still further4 object concerns the provision of simple and etlicientmeans for prethe envelope from leaking out while in use. -A stillfurther object concerns the provision of simple and'ecent means forregulating the supply of air that enters the device.

The invention is illustrated in the drawi of whichigure 1 is anelevation of the device; Fig. 2 is a section; Fi 3 is a perspective viewof the inner bag s owing how the layers are forced apart when the bagbisheld by the flap causing a strain on the ias of the bag;

Fig. 4 is an enlarged elevation of the funnel corner of the bag;

5 is a section on the line 5-5 of Fig. 6 is an enlarged section of thefunnel corner showin the manner in which it is folded when t e openingis closed and held closed; and

F10'. 7 is a rspective view of one of the Ventilating bolli plugs.

The form of the invention shown in the drawings is a lpreferred form,although it is understood t at modifications in the construction andarrangement of the parts and in the character offthe materials used maybe adopted without departing from the spirit of the invention as setforth in the appended claims.

. My'A invention comprises a fabric bag, canvas or "the like, one-thirdfilled with the following chemical mixture. 90 per centbne een Vcoatedwith a solution of CuClz-l-2H2O and H2O, 9 per cent KCl or 9-per centNaCl and 1 per cent CaCO3 or 1 per cent (MgonMgoHh-i-:aI-Lo. This fabricbag is prefera ly rectangular in shape and sewed along its edges. In onecorner of the bag the two layers of material are separated to form anopening through which water can be forced. Adjacent this opening twolayers of material are sewed together along lspaced lines which convergeinwardly to- :ward the center of the bag to form a funnel.

This corner of one of the layers of material 1s cut away shorter thanthe corresponding corner of the other layer so that the one cornerportion will extend beyond the other to be used as a flap to grip thematerial irmly in the hand causing a strain on the bias of the pad andforcing the two layers to separate at this point, the edge of the othercorner portion being bent over to insure a better seal when closing thefunnel.

A U-shaped metallic clip having one long side is attached to theextended flap ortion of the bag. The short side of the cip extends downon the inside of the bag to a point where it is to be bent over whenclosing the bag and the other side extends an equal distance beyond thatpoint. The clip is therefore double for one half its length whenfastened on the flap of thebag. The clip is made from a gauge metal thatwill bend easil in a sin le thickness but where it is double it willalmost impossible to bend it. For this reason the clip will always bendjust where you want it to fold and thus eliminate the danger of spillingout the hot chemicals during use. Therefore it can be seen that this newtype of clips performs another function other than merely holding thebag closed.

The bag is then placed within an envelo which is waterproof. Thisenvelope, on its inner surface, is provided with a plurallty ofirregular rows of ribs which space a considerable portion of theenvelope away from the outer surface of the bag so that air can get tothe chemical mixture through the fabric bag. The envelope is providedwith a plurality of Ventilating openings the inner edges of which have araised head -around them to prevent the condensation which forms on theinside of the envelope from leaking out through the openings while inuse.

In starting the chemical heater the funnel is opened b bending back themetal clip, one tablespoon u1 of water is poured in throu h the opening.The funnel is closed and t e bag inserted into the waterproof envelope.The chemical heater should be kneaded at once to distribute the 'wateruniformly through the mixture. Spontaneous generation of heat willresult 'by the H20 starting to oxidize the iron borings. The presence ofthe coating of CuClz-i-2H2O on the iron borings greatly accelerates thes eed in starting but it can not be used in arge quantities since it isnot stable in air. Therefore a quantity of NaCl or KCl is used toaccelerate the oxidization of the iron borings over a long period oftime. The heat nerated by this oxidization evaporates the ll'lzO anddries the chemical mixture out thus automatically stopping theoxidization after several hours of heating. This may be repeated severaltimes or the heater may be kept hot continuously -for several days byadding more water when it cools down. It may be kept hot until the ironis completely oxidized. The 'CaCO3 or (MgooshMgmmzJfsHzo jected todampness. The iron borings would not oxidize if it was not for theoxygen in the air that unites with the iron forming iron oxide. TheVentilating ribs on the inner surface of the envelope therefor aidsgreatly in uniformly distributing the air supplying oxygen to thechemical mixture which in turn generates a uniform temperaturethroughout the said mixture.

As shown in the drawings, the preferred form of the invention comprisesa bag l. formed of two layers of material sewed together except at onecorner (not shown). At this corner the material of one ont the layers iscut awa permitting the other corner of the other layer of material toextend therebeyond, as at2, to form a Hap extension which can be grippedin the hand, causing a stress on the bias of the bag and forcing orcausing the two layers to separate as shown in Figure 3. The layer whichis cut away, however, has its upper edge at the corner turned over, asat 3, to insure a better seal when closing the funnel. The extended flapportion is provided with a metallic clip 4 which is'bent doublethereover in a manner so as to eliminate at all times the dangers ofimproper closing of a'device of this character. Lines ofstitching 5 and6 extend inwardly toward the center of the bag and converge toward eachother. -'lhese lines are spaced apart and join the layers together toform a funnel, the water bein poured in between the layers of materialwithin an area defined byv these rows of stitching. As the Hap 2 is heldin the hand the layers of material tend to separate and causethestitching to form a simple funnel. When the water has been pouredin,'the extended ap 2 is bent over, as shown in Fig. 6, to cover thethis Leanser shorter Hap portion and the opening form@ therebetween7 therigidity of the metal clipl 4 keeping the opening clod.

The bag 1 is then put in an envelope 7 of waterproof material which isprovided with a pluralityof openings such as 8 for Ventilating purposes.These openings are connected on the inner surface of the bag by rows,such as 9 and 10, of irregular ribs or teats-which keep the Amajorportion of the surface of the envelope away from the outer lsur'ace ofthe bag so that air getting in through the openings 8 will suppl oxygento the chemical mixture uniform y which in turn generates a uniformtemperature throughout the chemical heater. The envelope 7 is providedwith a plurality of ventilatmg openings 8 the inner edg of which have araised bead around them to prevent thecondensation which forms on theinside il i of the envelope 'l from leaking out through the openings 8while in use.

The temperature of the chemicalheaterv sults in the construction andoperation oit the bag.

What I claim is 1 1. A chemical heating pad formed of two layers ofmaterial sewed together along their edges exce t at one corner, aportion of the material o one layer being cut away to mrmit the cornerof the other -layer to ed therebeyond in the form of a nap, whereby thepad can be supported by this nap thereby causing a stress on the bias ofthe uw? which `forces the two layers to separate at point. 2. A chemicalheating pad formed of two Mid layers of material sewed together alongtheir Y edges exce t at one corner, a portion of the material o? onelayer being cut away to permit the corner of the other layer to extendtherebeyond in the form of a Hap, whereby the pad can be gripped by thisflap, causing a stress on the bias of the pad which forces the twolayers to separate at this point, and rows ot stitch' t: extendin in aconver'n manner inwarly from t is cornerl f' t e pad to join the layersand form a sort of spout or funnel1 passage through which water can beoure P 3. A chemical heatin pad formed of two la ers of material sewetogether along their e ges exce t at one corner, a portion of thematerial o one layer beingcut away to perlll@ ist

mit the corner of the other layer to extend la@ therehedyond in the formof a Hapgwhere'by the A, a can be 'p ed b this a causing a stipess onthe bgilals lof thgpad whipoh forces the two layers to separate at thispoint, and form a funnel passage, and a U shape metal eiip having oneside shorter than the other, crimped over the extension Hap reinforcingthe ap with metal on both sides to a point.

where the Hap portion is adapted to be bent over to close the funnelpassage. 4i. A chemical heatin pad formed. of two ia ers of materialsewe together along their ges exceptat one corner, a portion of thematerial of one layer being out away to permit the corner of the otherlayer to extend therebeyond in the form of a Hap, whereby the pad can begripped by this Hap, causing a stress on the bias of the `pad. whichforces the two layers to separate at this point, and

form a funnel passage, and a U-sha-ped metal clip crimped over theextension flap reinforcing it with metal on both sides to a point wherethe Hap portion is adapted to be bent over with the other layer ofmaterial at the corner to close the funnel passa e.

MKLDRED AURELIA SMTH.

